Speedometer



Jan. 16, 1923.

' SPEEDOMETER.

FILED DEC. 22. I920.

1,442,128. 1. A'. coon/15s.

* "UNITED," starts Patented Jan. 16, 1923;

, COMPANY LIMITED, or LONDON, ENGLAND, A BRITISH L MITE LIABILITY COMPANY.

ea rs I JOSEPH ALBnR'roooMns, or LONDON, ENGLAND, .nssrenoa roa meanness; i

i v srnnnontnrnaj r Application filed December22, 192m Serial no,4352,4371

To all whom it may cancer m Be it known that I, JOSEPH ALBERT GOOMES sub'ect of the'Kin of En land. re

7 J b b 1 This invention is for improvements in or relating to speedometersof the type wherein a propeller-fan is driven from a moving part of the motor vehicle or other apparatus whose speed is to be ascertained, and an. in-

dicator-fan is placed in the current of air established by the propellenfan so that it is angularly displaced about its axis of. rotation by the said current, and the degree 01' such angular displacement is in proportion. to the speed of movement of the part where-f by the propeller-tan is driven. This type of speedometer further comprises an enclosing casing for the two fans and a separating partition in the form of a sleeve, which is smaller in diameter than the casing and has thepropeller-ian set at one open end and the indicator-fan at the other open end, and the air is made to travel through the partitioning sleeve in one direction and outside of it in the other direction between the exterior surface of the sleeve and the surrounding caslng.

In speedometers of this type, it has heretofore been the practice to make the separating partition cylindrical in form, and the diameter of thetwo fans to =be approximately equal to that of the interior diameter of the cylindrical sleeve; moreover, the propeller-fan has been made to drive the air through the sleeve. g

According to the present invention a speedometer of the type described has the propeller-fan and the indicator-fan sep arated by a partition whichi's smaller at the propeller-fan end thatit is at the indicatortan end, and the blades of the propeller-tan are made to extend beyond the circumference of the propeller-fan end'ot the separator and are arranged todirect the air away from the separator towards the end of the enclosing casing.

The invention is illustrated by way of ex- Figural is a central'vertical section show lng one form of speedometer according to v.

the invention, and

Figure 2 is a partial sectionth'rough the same taken a plane at right-angles to Fig. 1. a

' Like reference letters designate likepjarts I Y I The nstrument comprises a cylindrical,

throughoutboth views.

casing A in whichal'lthe-parts are enclosed,

and-a clip is attached to the casing for securing'the nstrument to a support; En ter ngthe casing through a boss A is a spindle B which can be attached in'any desired, 1 manner to a flexible or other shaft arranged to move with the partwhose speed is to'be measured, suchjas'a pinion driven, by a I lZOOthGCl-WVllGGl on the road-wheel of a motor-- vehicle. The spindle B carries: fast on it's toothed-wheel B and: this meshes with a pinionC which'is 'mounted' freely one fixed stud C ,f Fast on theipinion is an impeller" or propeller-fan D, and securedto this is a partition or .s'epa'rator D The separator comprises a sleeve in the'form ot a hollow f F truncated cone.

The propeller isjdriven in the direction indicated 'by the arrowon the partition D and the blades are so placed thatwhen driven in this direction they'drive the air towards the baok of the casing away from the partition. A spindle'E mounted at the front" end inv a bracket E and at theback end in the stud Ct, carries an'indicator:

fan-wheel F. This fan-wheel is mounted" within the partition D and'approximately fills the interior of the same, but the blades pro ect forwardly from the partition an.

amount that is approximately 25%" of the depth of the blades, and such forwardly pro-" jecting part has a wider sweep than that which lies withinthe partition. As' shown' in the drawing, the. amount which these blades project torward is' approximately 25% 0 the'total depth of the anwh'eei blades. Thesebla'des are set so: that they tend to turn the spindle. E IockWiseTas viewed from the front when an air current mpinge on the front of the 'fan'- is made to wheel.

The operation follows The propeller-"tan *i) eating is [the i at of this apparatus is las rection indicated by the arrow on ftheip an tition D establishes a current of air which moves towards the back of the casmg and is deflected. there'lrom round, the exterior of i the partition D to the front of the casing.

Here it is again deflected and returns though'the partitionv D and in so doing angularly deflects the indicator-fan F about its aXis of rotation, or about the axis of rotation of its spindle E. This spindle is controlled by a springK in known manner, and thus the angular displacement will be greater or less according to the degree of thrust of the air-current.

The spindle E carries the usual indicatorpointer G which moves over a dial G graduated to show the speed indicated.

The drum H is an ordinary mileage-counter driven by a spindle H which receives its motion from a pinion not shown in the drawing but which meshes with the wheel B WVhat I claim as my invention and desire to secure by Letters Patent is 1. In a speedometer, the combination with a case, of a sleeve mounted coaXially, therein with a free annular space provided be-- tween its periphery and the case, which sleeve is of such form that it presents a plain exterior surface, an impeller of larger diameter than the sleeve mounted coaXially in the case at one end of the sleeve with a free annular space between the periphery. of the impeller and the case, the blades 0f the impeller having parts thereof operative for moving the air through the sleeve in a direction towards it, extending partly across the adjacent open end of the sleeve, a "spring-controlled indicator fan wheel mounted coaXially with the impeller at the other end of the sleeve, and means 'for rotating the said impeller in such a direction as'to draw the air through the tan-wheel and through the sleeve and drive it against the adjacent end of the case away from the sleeve, for the purpose specified 2. Ina speedometenthe combination with a case, ofa sleeve mounted coaXially thereln with a free annular space provided between its periphery and the case, which sleeve is of such form that it presents a plain exterior surface, an impeller of larger diameter than the sleeve mounted coaXially in the case at one end of the sleeve with a free space between the periphery of the impeller and the case, the blades or the impeller having parts thereof operative for moving the air through the sleeve in a direction towards it, extending partly across the adjacent open end of the sleeve, a spring-controlled indicator fanwheel having blades of the sc'rewpropeller type mounted coaxially with the impeller at the other end of the sleeve, which blades project forward of the sleeve an amount that is approximately 25% of the total depth of the fan-wheel blades, and means for rotating said impeller in such a direction as to draw the air through the fan-wheel and through the sleeve and drive it against the adjacent end of the case away from thesleeve for thepurpose specified.

3. Ina speedometer, the combination with a case, of a sleeve in the form of a truncated 7 case, the blades of the impeller having parts thereof operative for moving the air through the sleeve in a direction towards it,extending partly across the adjacent open end of the sleeve, a spring controlled indicator f111-Wl18l mounted coaxially with the impeller at the other end of the sleeve, and means for rotating sald impeller 1n such a direction as to draw the air through the fan-' wheel and through the sleeve and drive it against the adjacent end of thev case away from the sleeve, for the purpose specified.

l. A speedometer, comprising, in combination a cylindrical case, an impeller mounted coaXially in the rear-o1": said case, a sleeve in the form of a truncated cone carried co axially by its smaller-end on the frontof said impeller, a free annular space being provided between the lnner perlphery of said case and the impeller and said sleeve,-

axially in the larger end of said sleeve, an

indicator operatively connected with said fan-wheel, and means for rotating said impeller so as to drive'the air against the back of the case, which sleeve is of such form that. it'presentsa plain exteriorsurface, an1n1 peller of larger diameter than the sleeve mounted coaXia-lly in the case at the rear end of the sleeve with a free space between the periphery of the impeller and the case, the blades of said impeller having parts thereof operative for moving the air through the sleeve in a direction towards it, extend ing partly across the adjacent open end "of the sleeve, a springcontrolled indicator :fan-

wheel mounted coaxially with the impeller at the front end of the sleeve, the blades of which fan-wheel project forwardof the 100 a spring-controlled fan-wheel mounted cov sleeve an amount that is approximately 25% of the total depth of the fan-wheel blades, and means for rotating said impeller in such a direction as to draw the air through the fan-wheel and through the sleeve and drive it against the adjacent end of the case away from the sleeve, for the purpose specified.

6. In a speedometer, the combination with a case, of a sleeve having an unobstructed throughway mounted coaxially therein with a free annular space provided between its periphery and the case which sleeve is of such form that it presents a plain imperfo rate exterior surface, an impeller of larger diameter than the sleeve mounted coaxially in the case at one end of the sleeve with a free annular space between the periphery of the impeller and the case, the blades of the impeller having parts thereof operative for moving the air through the sleeve in a direction towards it, extending partly across the adjacent open end of the sleeve a spring controlled indicator fan-wheel mounted c0 endof the case away from the sleeve, for the purpose specified.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

' JOSEPH ALBERT OOOMES.

Witnesses:

A. M. HAYWARD, H. T. RIDGE. 

